Please check that you have an internet connection and that your phone is registered/getting an IP address.
Please make sure the number you are calling has not been disconnected.
If you are calling a local number, please ensure that your dial plan is correct.
If SIP-ALG is enabled on your router, please try disabling then try again.
If you pay for a call plan, you may get an automated message about credit.
Please contact us for further information/assistance.